1. Field of the Invention
The present invention relates to a silver halide color photosensitive material which is of high photographic speed and is superior in image quality and which exhibits a small fluctuation in photographic properties due to a development process applied thereto.
2. Description of the Related Art
In the field of silver halide color photosensitive materials, to increase the photographic speed of photosensitive materials is an important object.
It is known that the photographic speed of silver halide photosensitive materials is generally determined depending upon the size of silver halide emulsion grains contained therein.
In other words, it is possible to increase the photographic speed by use of large silver halide emulsion grains. However, it is also well known that the graininess is deteriorated with increase in size of silver halide grains. There is a trade-off between the photographic speed and the graininess.
Therefore, to increase the photographic speed without deteriorating the graininess is the most basic and important problem for the performance of photosensitive materials.
A method is known in which increase in photographic speed without causing no deterioration of graininess is accomplished by incorporating a compound having at least three hetero atoms which do not react with an oxidized developing agent to a silver halide photosensitive material (see Japanese Patent Application KOKAI Publication No. (hereinafter also referred to as “JP-A-”) 2000-194085).
This method exhibits some effect of increasing in photographic speed. It, however, also exhibits some increase in fog fluctuation due to development process fluctuation, and therefore, is desired to be improved.
On the other hand, problems associated with the use of elemental silver in an antihalation layer or the like include an undesired increase in fog at image-forming layers. It is also known that this fog is very susceptible to development. There is known a method of reducing the undesired fog by use of a heterocyclic thiol compound having a defined Clog P (see JP-A-11-271930).
This method exhibits an effect of reducing fog. It, however, results in an increase in photographic property fluctuation due to storage of a photosensitive material, and therefore, some improvement is desired.